An auto-tracking spectrophotometer (ATS) measures and analyzes spectral data. Since spectral data provides the most complete and accurate description of color, an ATS is the ideal control system for both process and special color print jobs.
An ATS has a table for holding a color composition, a head for performing a scan of the color matrix, and a station, located at one end of the table. In order to use the ATS, an operator places a color graphic composition have a color target on the ATS platen. A vacuum pump is then energized so as to hold the composition onto the table.
The ATS head then scans the entire color target first to locate the beginning and ending points of the color target. After the beginning and ending of the color target are located, the ATS assumes that the color bar proceeds linearly between the beginning and ending of the color bar. Based upon this assumption, the ATS positions its data acquisition optics over what should be the color target, and then scans the area. After the head returns to the station, the measurement is then transmitted to a computer. Software on the computer displays an overview of the color data. The computer or an operator may then adjust the controls of a press used to more accurately reproduce the graphic composition.
ATS have proven invaluable in modern printing plants. However, they have limitations. Care must be taken by the operator of the ATS to align composition in the ATS. If not, the color target may be slightly curved when placed on the table. Further, if the composition is contained on a folded sheet of paper, additional care must be taken to compensate for the fold in the color target. If the color target is not properly aligned, the color target may not be accurately read.
Additionally, at least two scans are required by the ATS. The multiple scans may cause significant time delays. Finally, even with the multiple scans, the alignment of the color target may not be acceptable, resulting in faulty color information.
Further, the scan information is not transmitted to the computer until the head is returned to the station. This delays the time before the data is analyzed, resulting in delays in completing the print job.
An improved ATS which overcomes these problems is thus highly desirable.